As known, internal combustion engines can be divided into two main categories: the first category comprises the internal combustion engines provided with speed regulator, which is adapted to maintain the speed of rotation of the engine constant upon the variation of the load applied to the engine, and the second category comprises engines without speed regulator, regarding which the rotation speed varies as a function of the applied load.
The engines provided with regulator generally have a lever which is rotatably associated to the engine casing and it is arranged in the proximity of the controlled member which is designated to continuously regulate the speed, in particular in diesel engines such controlled member could be the injection pump, in engines provided with carburettor it could be the throttle of the carburettor or another member, whose actuation leads to a variation of the amount of fuel supplied to the combustion chamber.
Such lever is free to rotate, for a limited angle, with continuity, thus continuously varying, for example, the speed of the engine.
The lever arranged in proximity of the controlled member is, then, in turn controlled by a remote lever, arranged in a position accessible by a user, through return means, such as bowden cables, rigid rods or any other return means of the known type.
In order to transform an engine provided with such lever for controlling the continuous regulation of the speed in a preferential two-speed engine, there are known remote levers (i.e. accessible to the user) which have two or more stop positions angularly separated and spaced from each other.
A known remote lever of this type is described in the U.S. Pat. No. 4,949,591.
Such lever of the known type has a discrete angular stroke so as to be able to transfer the rotation to the lever arranged in proximity of the controlled member and thus, the stop positions, for example at the position of minimum speed of the engine and maximum speed of the engine, are necessarily angularly spaced from each other.
However, a drawback revealed in these remote levers lies in the fact that they however allow the positioning of the lever in intermediate positions interposed between the minimum and maximum speed positions, practically maintaining the engine at a continuously adjustable speed.
An object of the present invention is to overcome the aforementioned drawbacks of the prior art, through a simple, rational and inexpensive solution.
In practice, an object of the present invention is to efficiently transform a continuously adjustable speed engine into an engine with imposed two speeds, substantially preventing the possibility of adjusting the speed in the intermediate positions to the minimum and maximum speed or optimal speed position.